Aneroid barometer



Dec. 28 1926. 1,612,344

R. ARNISON ANEROID BAROMETER Filed April 28,, 1926 INVENTOR Rowland firm/6017 Patented Dec. 28, 1926.

UNITED STATES PATENT OFFICE.

ROWLAND ARNISON, OF SOUTH WOODFORD, LONDON, ENGLAND, ASSIGNOR T0 TAYLOR INSTRUMENT COMPANIES, OF ROCHESTER, NEW YORK, A CORPORATION OF. NEW

YORK.

Application filed April 28, 1926, Serial No. 105,199, and in Great Britain May 26, 1925.

This invention is for improvements in or relating to aneroid barometers and has for its object to provide a simpler means of mounting the vacuum drum or drums, to gether with the adjustment for the spring tension, than has heretofore been proposed.

According to one feature of this invention an aneroid barometer mechanism is provided with connecting means whereby the drum may be anchored toa relatively fixed member and the opposite side is provided with connecting means for engaging with a tension element, characterized in that one of said connecting means comprises a device (for example a longitudinally adjustable pin) for adjusting the length of the connecting means.

The term barometer mechanism as used herein includes the magnifying mechanism, but excludes the dial and pointer. The term drum as used herein includes a drum s'ystem. By the term side is meant either of those parallel faces of the drum which move relatively to one another under the atmospheric pressure.

Each of the' aforsaid connecting means may comprise a centrally disposed pin.

According to one feature of the invention the carrier for the drum may comprise a tension device formed with parts adjacent both of two opposite sides of the drum, which parts are connected to the drum by the connecting means aforesaid; and the latter may constitute the sole means of support for the drum.

The tension device may comprise aflat plate of resilient material bent into U-form and arranged to receive the drum between the limbs of the U and to hold the same under tension by means of the aforesaid connectingmeans. and one limb of the U may constitute the relatively fixed part aforesaid.

The invention further includes an aneroid barometer mechanism in the form of a unitary structure comprlsing 1n combination a drum. a flat plate of resilient material bent into U-form, with the drum disposed be-i tween its limbs and with the opposite sides of the drum operatively connected respectively with the adjacent limbs. and a magnifying mechanism and tensioning-means also carried-on said resilientplate.

'to the drum and a sleeve-nut 5 screw, which nut has at its outer end an ordinary notched screw-head. The outer According to another feature of this invention the device for adjusting the length of the connecting means may comprise a nut and screw, one fixed to the drum and the other rotatably engaged with the tension device or the fixed member, as the case may be, and arranged to transmit the pull of the tension device to the drum. The said rotatable member may have rightand lefthend threads, one of which threads is engaged with a part of, or a part connected to, the drum and the other thread is engaged with a part of,'or a part connected to, the tension device for the fixed member, as the case may be, so that for one revolution of the rotatable member the endwise displacement of the pin will equal the sum of the thread pitches.

' In order that the invention may be more clearly understood one preferred form will now be described, by way of example only,

with the aid of the accompanying drawings in which Figure 1 shows a side View of a barometer mechanism according to this invention, mainly in elevation but partly in central section, and

Figure 2 is asection on the line 22 of Figure 1 looking in the direction of the arrows.

According to one method of carrying out this invention a single vacuum drum 1 is mounted between the limbs 2 and 3 of a U- shaped spring whereby tension is applied to the drum constituting the carrier. Limb 2 of the U 'is made longer and wider than limb 3 to provide a base whereby the spring can be secured in any convenient enclosing casing. The drum has two central pins secured to its opposite sides, one of which, namely that which is towards the longer and wider limb 2 of the U-shaped carrier is longitudinally adjustable. This pin comprises'a left-handed screw 4 rigidly secured on said surface of the sleeve-nut is screw-threaded with a right-handed thread and en ages a correspondingly threaded bush 6 in the limb 2 of the spring. Obviously, the directions of screw-threads on the pin and on the exterior of the sleeve-nut can be reversed, i. 0.,

the pin can have a right-handed thread and the sleeve-nut a left-handed thread. The bush 6 has an enlarged portion to provide a shoulder 7, and the reduced portion is flatted at the sides, as shown in Figure 2 at 8, and extends through a correspondingly shaped hole in the limb 2 of the spring; the shoulder 7 bears against the underside or back of the spring. The pin 9 on the opposite side of the drum extends through a hole in the limb 3 of the spring, and is secured by a cross-pin having a knife edge engaging in a notch on the outer surface of the limb 3.

The drum 1 is introduced between the limbs 2 and 3 of the spring with the latter compressed, so that, when in position, the sides of the drum are expanded against atmospheric pressure which will tend to press them in. threaded sleeve-nut 5 is rotated by means of its slotted head in one direction or the other, and thereby the distance between the limb 2 of the spring and the corresponding side of the drum, or the effective length of the 7 pin, is varied. The thread on the exterior of the sleeve-nut serves as a thrust-receiving means to prevent the sleeve-nut from being drawn through the bush under the action of the spring. The flatted portion 8 of the bush, in which the sleeve-nut screws, prevents rotation of the bush itself, and the,

drum is prevented from rotating by the knife-edged pin 10 engaging in the notch aforesaid on the outer surface of the limb 3.

The indicating-needle 11 and the magnifying mechanism with its return spring 12 are mounted on the limb 2 of the spring, so that the spring, with the parts thereon, constitutes the entire barometer mechanism. The dial 1?) and dial-carrying frame 14 are also mounted on the limb 2 of the spring.

It will be appreciated that the means for securing the drum and that for adjusting the same are combined; further the spring itself constitutes the entire carrier for the drum, magnifying mechanism and dial, and can be secured direct into a suitable casing, or the dial-carrying frame may constitute means whereby the spring and all To adjust the drum the screw including means for varying its effective length, and a loose connection between the other leg and the opposite side of the drum.

2. In an aneroid barometer, the combination with the drum, of pin-like projections on the opposite faces of the drum, 2. U-

shaped member of resilient material having its legs connected to the said pins and means connected with" one of the projections and the corresponding leg of said member for' varying the effective length of the projection, including an element movable relatively -to both the projection and the leg.

3. An apparatus according to claim 2, wherein the saidelement is of tubular form provided interiorly and exteriorly with screw threads having corresponding screwthreaded engagement with the projection and the leg.

4. Apparatus according to claim 1, wherein the means for varying the effective length of the connection comprises a threaded projection on the drum, a. tubular member exteriorly connected to the leg of the spring and provided interiorly with screw-threads,- and a tubular element having exterior screwthreads co-operating with the screw-threads of said member and having interior screw threads cooperating with the screw-thread on the projection.

5. Apparatus according to claim 1, including means for translating the relative movement of the opposite faces of the drum, said means being entirely supported on the said spring.

I In testimony whereof I afiix my signature.

ROWLAND ARNISON. 

